apd VS be

https://github.com/cockroachdb/apd is currently the best implementation in the ecosystem (performance, correctness). Have you already evaluated it?

FWIW I think cockroachdb/apd is the best third party option. While building bojanz/currency I've evaluated and benchmarked the others and found them either less maintained, slower, or both.

I have a package for handling currency amounts and calculations that is based on cockroachdb/apd, in my opinion the best arbitrary-precision decimal implementation in Go right now. So, I can offer a bit of insight.

The best decimal package is still cockroachdb/apd. I wrap it in bojanz/currency for money handling.

https://github.com/cockroachdb/apd remains the best decimal library for Go (ericlagergren/decimal is faster but unmaintained).

Note: In benchmarks ericlagergren/decimal was noticeably faster than cockroachdb/apd, but it has known bugs when used with go mod, so I decided to wait and go with cockroachdb/apd for now. The Amount struct wraps the decimal implementation completely, making it easy to do the swap later without breaking BC.

For testing, use be

I made a package like that: https://github.com/carlmjohnson/be. It’s probably my most frequent use of generics.

I spent the last week working on one of these: https://github.com/carlmjohnson/be. Some initial thoughts I have are that the error messages basically don’t matter because if the test fails you’re going to dig into the line where the failure happens anyway.